This invention relates to a self adjusting mechanism incorporated into a pliers that enables the user to grip and lock the pliers using only one hand during the operation.
Pliers are used in a variety of situations to grip a bolt, nut, wire, or other items. The general design uses the leverage of two elongated pieces having a handle portion at one end and a jaw piece at the other end. Both pieces are connected together at a pivot pin. When the handle portions are squeezed together, the jaws of the pliers grab the object desired. The length of the handle portions determines the amount of gripping power of the jaws.
Various locking mechanisms are on the market, such as the popular vise grips. These locking mechanisms use a series of hinges to lock the jaws of the pliers together. However, while a first hand grips the handles of the pliers, the other hand is used to turn a screw to adjust the locking mechanism. This means that the items to be gripped must be placed into the jaws snugly prior to the adjustment of the locking mechanism. Thus, such a mechanism requires the use of two hands in order to effectively grip and adjust the locking mechanism to lock an item with the vise grips.
An object this invention is to overcome the problem of using both hands to lock the pliers. This allows the user to perform other tasks with a free hand prior to and during the gripping and locking of the pliers. The invention overcomes this problem and others by providing pliers that allow for a single hand to hold and lock pliers. The locking mechanism comprises an arc shaped surface connected to one handle, and a hinged pressure contact on the other handle. The user uses a free finger on the hand gripping the pliers to pull a lever on the pressure contract to engage the pressure contact with the arc shaped surface. The contact transfers pressure to the jaws of the pliers to better hold an item in the jaws, while friction at the contact point keeps the handle with the pressure contact from moving with respect to the arc surface.